385 Matching Results

Search Results

Advanced search parameters have been applied.

Filtration Understanding: FY10 Testing Results and Filtration Model Update

Description: This document completes the requirements of Milestone 2-4, Final Report of FY10 Testing, discussed in the scope of work outlined in the EM31 task plan WP-2.3.6-2010-1. The focus of task WP 2.3.6 is to improve the U.S. Department of Energy’s (DOE’s) understanding of filtration operations for high-level waste (HLW) to improve filtration and cleaning efficiencies, thereby increasing process throughput and reducing the Na demand (through acid neutralization). Developing the cleaning/backpulsing requirements will produce much more efficient operations for both the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Savannah River Site (SRS), thereby significantly increasing throughput by limiting cleaning cycles. The scope of this work is to develop the understanding of filter fouling to allow developing this cleaning/backpulsing strategy.
Date: April 4, 2011
Creator: Daniel, Richard C.; Billing, Justin M.; Burns, Carolyn A.; Peterson, Reid A.; Russell, Renee L.; Schonewill, Philip P. et al.
Partner: UNT Libraries Government Documents Department

Repair of overheating linear accelerator

Description: Los Alamos Neutron Science Center (LANSCE) is a proton accelerator that produces high energy particle beams for experiments. These beams include neutrons and protons for diverse uses including radiography, isotope production, small feature study, lattice vibrations and material science. The Drift Tube Linear Accelerator (DTL) is the first portion of a half mile long linear section of accelerator that raises the beam energy from 750 keV to 100 MeV. In its 31st year of operation (2003), the DTL experienced serious issues. The first problem was the inability to maintain resonant frequency at full power. The second problem was increased occurrences of over-temperature failure of cooling hoses. These shortcomings led to an investigation during the 2003 yearly preventative maintenance shutdown that showed evidence of excessive heating: discolored interior tank walls and coper oxide deposition in the cooling circuits. Since overheating was suspected to be caused by compromised heat transfer, improving that was the focus of the repair effort. Investigations revealed copper oxide flow inhibition and iron oxide scale build up. Acid cleaning was implemented with careful attention to protection of the base metal, selection of components to clean and minimization of exposure times. The effort has been very successful in bringing the accelerator through a complete eight month run cycle allowing an incredible array of scientific experiments to be completed this year (2003-2004). This paper will describe the systems, investigation analysis, repair, return to production and conclusion.
Date: January 1, 2004
Creator: Barkley, Walter; Baldwin, William; Bennett, Gloria; Bitteker, Leo; Borden, Michael; Casados, Jeff et al.
Partner: UNT Libraries Government Documents Department

Prevention of iron-sulfide deposition in petroleum processing. Final CRADA report.

Description: The purpose of this CRADA extension which effectively ended in 2003 was to quantify the effect of iron-sulfide formation on the fouling propensity of crude oil. The specific objectives are focused on fouling of the Crude Distillation Unit (CDU-1) at the Shell Refinery in Mobile, Alabama. The technical approach consists of analyzing the plant data, chemical analysis of crude oil to detect key precursors, performing refinery tests using the Argonne Field Fouling Unit, and verifying the effectiveness of a physical device of tube insert and enhanced tubes to change threshold conditions and thereby reducing fouling.
Date: March 25, 2010
Creator: Doctor, R. D.; Panchal, C. B. & Systems, Energy
Partner: UNT Libraries Government Documents Department

Microbially Induced Iron Oxidation: What, Where, How

Description: From the results of the different bacterial cells seen, it is fairly certain that Gallionella is present because of the bean-shaped cells and twisted stalks found with the TEM. The authors cannot confirm, though, what other iron-oxidizing genera exist in the tubes, since the media was only preferential and not one that isolated a specific genus of bacteria. Based on the environment in which they live and the source of the water, they believe their cultures contain Gallionella, Leptothrix, and possibly Crenothrix and Sphaerotilus. They believe the genus Leptothrix rather than Sphaerotilus exist in the tubes because the water source was fresh, unlike the polluted water in which Sphaerotilus are usually found. The TEM preparations worked well. The cryogenic method rapidly froze the cells in place and allowed them to view their morphology. The FAA method, as stated previously, was the best of the three methods because it gave the best contrast. The gluteraldehyde samples did not come out as well. It is possible that the gluteraldehyde the authors prepared was still too concentrated and did not mix well. Although these bacteria were collected from springs and then cultured in an environment containing a presumably pure iron-bearing metal, it seems the tube already containing Manganese Gradient Medium could be used with a piece of metal containing these bacteria. A small piece of corroding metal could then be inserted into the test tube and cultured to study the bacteria.
Date: August 15, 2000
Partner: UNT Libraries Government Documents Department

Research and development to overcome fouling of membranes. Final report

Description: To overcome fouling of membranes, SRI International is developing a unique piezoelectric backing for ultrafiltration membranes. This backing is capable of producing local turbulence next to the membrane to minimize concentration polarization and the rate of buildup of solutes and particulate matter on the membrane surface. We have studied piezoelectrically assisted ultrafiltration in more detail, with the objective to apply this process to industrial ultrafiltrations. We conducted several ultrafiltration experiments on flat sheet membranes with model dextran solutions and with electrocoat paint to study flux enhancement as a function of parameters such as feed flow rate, feed pressure, as well as the piezodriver-membrane system.
Date: November 1, 1998
Creator: Narang, S.C.; Sharma, S.K.; Hum, G.; Ventura, S.C.; Roberts, D.L.; Gottschlich, D. et al.
Partner: UNT Libraries Government Documents Department

Ocean Thermal Energy Conversion (OTEC) Programmatic Environmental Analysis: Volume 1

Description: This programmatic environmental analysis is an initial assessment of OTEC technology considering development, demonstration and commercialization; it is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties.
Date: January 1980
Creator: Sands, M. Dale
Partner: UNT Libraries Government Documents Department

Project Calcium

Description: Fouling problems in utility boilers have been classified into two principal types: high-temperature and low-temperature fouling. A multiclient-sponsored program was initiated at the Energy and Environmental Research Center (EERC) to better understand the causes of low-temperature fouling when burning high-calcium western US coals. The goals of Project Calcium were to define the low-temperature deposition problem, identify the calcium-based components that are responsible for the formation of the deposits, develop ways to predict their formation, and identify possible methods to mitigate the formation of these deposits. To achieve the goals of Project Calcium, detailed sampling of utility boilers and laboratory-scale studies coupled with state-of-the-art methods to determine the inorganic components in coals and coal ash-derived materials were conducted. Boiler Sampling was also performed. The work involved sampling coal, entrained ash, deposits and slags from five full-scale utility boilers combined with detailed advanced characterization of the materials. The results of this work aided in identifying the key phenomena to focus the laboratory studies and in model verification. Field testing was conducted at three utilities.
Date: September 1, 1992
Creator: Hurley, J.P.; Benson, S.A.; Erickson, T.A.; Allan, S.E. & Bieber, J.
Partner: UNT Libraries Government Documents Department

Advanced coal liquefaction. Final quarterly report, July 1, 1994--September 31, 1994

Description: In this quarter, the authors investigated means to overcome the membrane fouling in the presence of tetraline at 150{degrees}C. Previously, it was indicated that tetraline underwent degradation at this temperature. Further, it was identified that this reaction could be minimized if one purged tetraline with nitrogen. It was hypothesized that tetraline could be stable at 150{degrees}C in the absence of oxygen. In this quarter, the authors attempted to apply the similar concept in the membrane filtration system. The entire filtration was thoroughly purged with nitrogen before introducing tetraline. Also during filtration, the collection bottle was purged with nitrogen. The permeate stream was maintained vacuum. Under this condition, the tetraline collected from reject and permeate did not show any chemical degradation. It is believed that the porous surface of Al{sub 2}O{sub 3}/SiO{sub 2} membranes may act as a catalyst for the degradation of tetraline. The degradation products, likely polymeric, fouled the membrane. The above tests were repeated and a similar fouling phenomenon was observed.
Date: April 1, 1995
Partner: UNT Libraries Government Documents Department

Filtration engineering study to upgrade the ETF

Description: Filtration technologies are evaluated which have potential to augment or upgrade the 200 Area Effluent Treatment Facility. The study was written in anticipation of treating future waste waters that have high fouling potentials. The Three ultrafilters judged to be capable of treating future waste waters are: hollow fiber, tubular, and centrifugal
Date: October 18, 1995
Creator: McDonald, F.N.N.
Partner: UNT Libraries Government Documents Department

Analysis of Exxon crude-oil-slip stream coking data

Description: Fouling of pre-heat train heat exchangers and process heaters used for the crude-distillation unit is a major unsolved problem which costs the industry in terms of energy inefficiency and productivity loss. The complexity of the fouling problem has prevented the industry from developing effective mitigation methods. Coking is a general term used for fouling at high temperatures, because the structure of the deposition resemblance to coke. Exxon Research and Engineering Co. conducted a joint research project with the US Department of Energy. One part of the research was to conduct coking experiments for crude oil subjected to heat fluxes greater than typical industrial conditions. In the present study, the coking data are re-analyzed and a simplified model is developed for predicting threshold fouling conditions. Recommendations are made for future experiments and analysis of the laboratory and field data.
Date: December 31, 1995
Creator: Ebert, W. & Panchal, C.B.
Partner: UNT Libraries Government Documents Department

Algae control for hydrogeneration canals

Description: The purpose of this Cooperative Research and Development Agreement (CRADA) was to assess and develop control practices for nuisance algae growth in power canal that delivers water to hydro-generation facilities. This growth results in expenditures related not only to lost generation but also labor and materials costs associated with implementing remediation procedures. On an industry-wide basis these costs associated with nuisance algal growth are estimated to be several million dollars per year.
Date: February 16, 1997
Creator: Grahovac, P.
Partner: UNT Libraries Government Documents Department

Study of soluble scale fouling control in high solids black liquor concentrators

Description: The quarterly project review meeting was held at IPST on August 2, 1999 and was attended by IPST, Georgia Tech, and ORNL principal investigators, members of the Industrial Advisory Group, and a U.S. DOE representative. Although steady progress is being made, this project is currently behind schedule. The specific tasks that are behind schedule, the reasons for the delays, and the expected completion dates are discussed. The remaining tasks are either on schedule, or have not been started.
Date: September 30, 1999
Creator: Frederick, W. J.; Chen, F.; Hsieh, G.; Lien, S.; Murphy, R.W. & Rousseau, R.W.
Partner: UNT Libraries Government Documents Department

Evaluation of Gas Reburning and Low-NOx Burners on a Wall-Fired Boiler; a DOE Assessment

Description: The results from the GR-LNB technology demonstrated by EER at Cherokee Station approached, but did not meet, the CCT project's performance objectives. Acceptable unit operability was achieved with both the GR and the LNB components. The gas reburning component of the process appears to be broadly applicable for retrofit NO{sub x} control to most utility boilers and, in particular, to wet-bottom cyclone boilers, which are high NO{sub x} emitters and are difficult to control (LNB technology is not applicable to cyclone boilers). GR-LNB can reduce NO{sub x} to mandated emissions levels under Title IV of the CAAA without significant, adverse boiler impacts. The GR-LNB process may be applicable to boilers significantly larger than the demonstration unit, provided there is adequate dispersion and mixing of injected natural gas. Major results of the demonstration project are summarized as follows: NO{sub x}-emissions reductions averaging 64% were achieved with 12.5% gas heat input in long-term tests on a 158-MWe (net) wall-fired unit. The target reduction level of 70% was achieved only on a short-term basis with higher gas consumption. The thermal performance of coal-fired boilers is not significantly affected by GR-LNB. Convective section steam temperatures can be controlled within acceptable limits. Thermal efficiency is decreased by a small amount (about 0.8%), because of increased dry gas loss and higher moisture in the flue gas as a result of the GR process. Furnace slagging and convective section fouling can be adequately controlled. Because of the higher hydrogen/carbon (H/C) ratio of natural gas compared with coal, use of the GR process results in a modest reduction in CO{sub 2} emissions. SO{sub 2} and particulate emissions are reduced in direct proportion to the fraction of heat supplied by natural gas.
Date: February 28, 2001
Creator: National Energy Technology Laboratory (U.S.)
Partner: UNT Libraries Government Documents Department

Fouling of HVAC fin and tube heat exchangers

Description: Fin and tube heat exchangers are used widely in residential, commercial and industrial HVAC applications. Invariably, indoor and outdoor air contaminants foul these heat exchangers. This fouling can cause decreased capacity and efficiency of the HVAC equipment as well as indoor air quality problems related to microbiological growth. This paper describes laboratory studies to investigate the mechanisms that cause fouling. The laboratory experiments involve subjecting a 4.7 fins/cm (12 fins/inch) fin and tube heat exchanger to an air stream that contains monodisperse particles. Air velocities ranging from 1.5-5.2 m/s (295 ft/min-1024 ft/min) and particle sizes from 1--8.6 {micro}m are used. The measured fraction of particles that deposit as well as information about the location of the deposited material indicate that particles greater than about 1 {micro}m contribute to fouling. These experimental results are used to validate a scaling analysis that describes the relative importance of several deposition mechanisms including impaction, Brownian diffusion, turbophoresis, thermophoresis, diffusiophoresis, and gravitational settling. The analysis is extended to apply to different fin spacings and particle sizes typical of those found in indoor air.
Date: July 1, 2001
Creator: Siegel, Jeffrey & Carey, Van P.
Partner: UNT Libraries Government Documents Department


Description: The accumulation of slagging and fouling ash deposits in utility boilers has been a source of aggravation for coal-fired boiler operators for over a century. Many new developments in analytical, modeling, and combustion testing methods in the past 20 years have made it possible to identify root causes of ash deposition. A concise and comprehensive guidelines document has been assembled for solving ash deposition as related to coal-fired utility boilers. While this report accurately captures the current state of knowledge in ash deposition, note that substantial research and development is under way to more completely understand and mitigate slagging and fouling. Thus, while comprehensive, this document carries the title ''interim,'' with the idea that future work will provide additional insight. Primary target audiences include utility operators and engineers who face plant inefficiencies and significant operational and maintenance costs that are associated with ash deposition problems. Pulverized and cyclone-fired coal boilers are addressed specifically, although many of the diagnostics and solutions apply to other boiler types. Logic diagrams, ash deposit types, and boiler symptoms of ash deposition are used to aid the user in identifying an ash deposition problem, diagnosing and verifying root causes, determining remedial measures to alleviate or eliminate the problem, and then monitoring the situation to verify that the problem has been solved. In addition to a step-by-step method for identifying and remediating ash deposition problems, this guideline document (Appendix A) provides descriptions of analytical techniques for diagnostic testing and gives extensive fundamental and practical literature references and addresses of organizations that can provide help in alleviating ash deposition problems.
Date: April 1, 2001
Creator: Zygarlicke, Christopher J.; McCollor, Donald P.; Benson, Steven A. & Gunderson, Jay R.
Partner: UNT Libraries Government Documents Department

Development of an analytical model for organic-fluid fouling

Description: The research goal of this project is to determine ways to effectively mitigate fouling in organic fluids: hydrocarbons and derived fluids. The fouling research focuses on the development of methodology for determining threshold conditions for fouling. Initially, fluid containing chemicals known to produce foulant is analyzed; subsequently, fouling of industrial fluids is investigated. The fouling model developed for determining the effects of physical parameters is the subject of this report. The fouling model is developed on the premise that the chemical reaction for generation of precursor can take place in the bulk fluid, in the thermal-boundary layer, or at the fluid/wall interface, depending upon the interactive effects of fluid dynamics, heat and mass transfer, and the controlling chemical reaction. In the analysis, the experimental data are examined for fouling deposition of polyperoxide produced by autoxidation of indene in kerosene. The effects of fluid and wall temperatures for two flow geometries are analyzed. The results show that the relative effects of physical parameters on the fouling rate differ for the three fouling mechanisms. Therefore, to apply the closed-flow-loop data to industrial conditions, the controlling mechanism must be identified.
Date: October 1, 1994
Creator: Panchal, C.B. & Watkinson, A.P.
Partner: UNT Libraries Government Documents Department

Fouling characteristics of compact heat exchangers and enhanced tubes.

Description: Fouling is a complex phenomenon that (1) encompasses formation and transportation of precursors, and (2) attachment and possible removal of foulants. A basic understanding of fouling mechanisms should guide the development of effective mitigation techniques. The literature on fouling in complex flow passages of compact heat exchangers is limited; however, significant progress has been made with enhanced tubes.
Date: July 15, 1999
Creator: Panchal, C. B. & Rabas, T. J.
Partner: UNT Libraries Government Documents Department

Advanced coal liquefaction. Final quarterly report, January 1, 1995--March 31, 1995

Description: In this quarter, carbon-coated ceramic membrane was used in the permeation of tetralin and compound No. 9/tetralin. The carbon coating was applied in the silica-modified ceramic membrane to minimize the degradation of tetralin (as solvent) on the membrane surface. Thus, the fouling is much reduced. An extended permeation run can be performed without difficulty. This carbon coated product is thus adopted for our study from now on. Two modified ceramic membranes with pore size < 40 {angstrom} were tested. The one with a larger pore size (C-Si286) exhibited separation of compound No. 9 from tetralin at 300{degrees}C, but not at 400{degrees}C; while the one with a smaller pore size (C-Si272) showed separation of compound No. 9 at 400{degrees}C. Both of them will be used for our future study involving reactions. The catalytic membrane reactor concept was also demonstrated in the separation study conducted above. Due to the use of carbon-coated membrane, compound No. 9 decomposed at 400{degrees}C through the membrane, while no decomposition was found in the feed. This observation indicates compound No. 9 undergoes catalytic reaction on the carbon-coated membrane surface. In the next quarter, the membrane will be packed with the carbon catalyst to enhance the decomposition ratio.
Date: September 1, 1995
Partner: UNT Libraries Government Documents Department

Development of methods to predict agglomeration and disposition in FBCs

Description: This 3-year, multiclient program is providing the information needed to determine the behavior of inorganic components in FBC units using advanced methods of analysis coupled with bench-scale combustion experiments. The major objectives of the program are as follows: (1) To develop further our advanced ash and deposit characterization techniques to quantify the effects of the liquid-phase components in terms of agglomerate formation and ash deposits, (2) To determine the mechanisms of inorganic transformations that lead to bed agglomeration and ash deposition in FBC systems, and (3) To develop a better means to predict the behavior of inorganic components as a function of coal composition, bed material characteristics, and combustion conditions.
Date: November 1, 1995
Creator: Mann, M.D.; Henderson, A.K.; Swanson, M.K. & Erickson, T.A.
Partner: UNT Libraries Government Documents Department

Use of ceragenins to create novel biofouling resistant water-treatment membranes.

Description: Scoping studies have demonstrated that ceragenins, when linked to water-treatment membranes have the potential to create biofouling resistant water-treatment membranes. Ceragenins are synthetically produced molecules that mimic antimicrobial peptides. Evidence includes measurements of CSA-13 prohibiting the growth of and killing planktonic Pseudomonas fluorescens. In addition, imaging of biofilms that were in contact of a ceragenin showed more dead cells relative to live cells than in a biofilm that had not been treated with a ceragenin. This work has demonstrated that ceragenins can be attached to polyamide reverse osmosis (RO) membranes, though work needs to improve the uniformity of the attachment. Finally, methods have been developed to use hyperspectral imaging with multivariate curve resolution to view ceragenins attached to the RO membrane. Future work will be conducted to better attach the ceragenin to the RO membranes and more completely test the biocidal effectiveness of the ceragenins on the membranes.
Date: December 1, 2008
Creator: Hibbs, Michael R.; Altman, Susan Jeanne; Feng, Yanshu (Brigham Young University, Provo, UT); Savage, Paul B. (Brigham Young University, Provo, UT); Pollard, Jacob (Brigham Young University, Provo, UT); Sanchez, Andres L. (LMATA, Albuquerque, NM) et al.
Partner: UNT Libraries Government Documents Department

Environmentally Safe Control of Zebra Mussel Fouling

Description: The two primary objectives of this USDOE-NETL contract were successfully achieved during the project: (1) to accelerate research on the development of the bacterium Pseudomonas fluorescens strain CL145A (Pf-CL145A) as a biocontrol agent for zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis)--two invasive freshwater bivalve species that are infesting water pipes in power plants; and (2) to identify a private-sector company that would move forward to commercialize Pf-CL145A as a substitute for the current polluting use of biocide chemicals for control of these dreissenid mussels in power plant pipes.
Date: February 29, 2008
Creator: Molloy, Daniel
Partner: UNT Libraries Government Documents Department